1. Field of the Invention
The present invention relates to a pixel processing method and a related apparatus, and more particularly, to a pixel processing method and a related apparatus which performs a green color component value adjustment upon a first pixel within a pixel block while simultaneously computing all color component values of a second pixel within the pixel block.
2. Description of the Prior Art
In a conventional image processing system, when an image sensor detects an exterior image, the image sensor generates color component values of each pixel and transmits the color component values to line buffers of an image signal processor (ISP). The color component values will be temporarily stored into the line buffers, wherein each pixel only has one color component value corresponding to one color, which is illustrated in FIG. 1. As shown in FIG. 1, a color filter array 10 is generated by the fact that the image sensor of the conventional image processing system detects the exterior image. Each row of the color filter array 10 is composed of different color component values of each pixel. As can be seen from FIG. 1, the first row of color filter array 10 is alternately arranged by red and green (R and G) color components to store the color components values of each pixel, and the second row is alternately arranged by green and blue (G and B) color components to store the color component values of each pixel, and so on. However, each pixel must finally have information of three color component values (R, G and B color components) so that the detected image can be precisely displayed on a display device. Thus, pixels with a single color component value in the color filter array 10 should be further processed and computed in order to make each pixel have three R, G, and B color component values, and then the pixels with three color component values are transmitted to a display driver. Accordingly, the display driver drives the display device according to the R, G and B color component values of each pixel to display the detected exterior image.
There are two steps that need to be performed upon the color filter array 10 to obtain all three R, G, and B color component values of each pixel. The first step is green color value adjustment, and the second step is interpolation. There are two kinds of green color value adjustments, one of which is Gr balance adjustment and the other of which is Gb balance adjustment. The so-called Gr balance adjustment adjusts the green color values of the green color components within the rows of the color filter array 10 where the red color components are located, such as the green color values G12, G14, G32 and G34 shown in FIG. 1. The so-called Gb balance adjustment is to adjust the green color values of the green color components within the rows of the color filter array 10 where the blue color components are located, such as the green color values G21, G23, G25, G41, G43, and G45 shown in FIG. 1. Generally, only one of the Gr balance adjustment and Gb balance adjustment will be performed upon the color filter array 10. In other words, the Gr balance adjustment and the Gb balance adjustment cannot be performed upon the color filter array at the same time. Once the green color value adjustment is performed upon the color filter array 10, all green color values within the color filter array 10 can be deemed as adjusted. Then, an interpolation operation will be performed upon the adjusted color filter array 10 to generate three R, G, and B color component values of each pixel. To take the color filter array 10 shown in FIG. 1 as an example, the green color value adjustment and the interpolation are separately performed. During the green color value adjustment of the color filter array 10 (e.g. adjustment performed upon the green color value G23), two line buffers are required. In addition, a further four line buffers are required for performing an interpolation operation upon the adjusted color filter array 10 (e.g. for the red color value R33). As a result, the conventional method in total needs six line buffers to compute the R, G and B color component values of each pixel within the color filter array 10. Hence, how to reduce the number of line buffers used by the ISP in order to decrease hardware costs has become a problem that manufacturers need to solve.